1. Field of the Invention
The present invention generally relates to a touch system and a touch method thereof, and more particularly to a projection touch system and a projection touch method thereof
2. Description of Related Art
With the development of the electronic technology and the optical technology, the projection touch system is widely used by portable devices to solve the inconvenience of carrying and using the physical input interface. Through the projection touch system, users may input information as using the physical input interface without holding the heavy device.
For correctly inputting the information, a virtual input image in conventional projection touch system is provided to users, and a detecting system detects and analyzes a relative position of the user on the virtual input image. FIG. 1 illustrates a schematic diagram of a projection touch system in the related art. Referring to FIG. 1, a virtual input image 110 is provided to a user on a projection plane 120 by a projection touch system 100. The detecting system 130 performs scanning by a detecting light beam 132a from one side of the virtual input image 110. When the detecting light beam 132a encounters the user's finger U1 or any object manipulated by the user, a reflected light beam 132b or a scattered light beam 132c may be detected by detectors 134, and the position of the user's finger U1 can be obtained by the detecting system 130. However, a dead zone is also formed on the projection plane 120 due to the block of the user's finger U1. The detecting system 130 is unable to detect another object behind the user's finger U1 in the dead zone. Accordingly, the information inputted by the user may be incomplete.
Therefore, to provide a projection touch system eliminating the dead zone with fewer elements is still a main topic for the persons skilled in this art.